The Department of State is asking county election officials to verify the information. Election supervisors are contacting voters and if someone is not a citizen, their name will be dropped from the voter rolls.

But an initial list drawn up by the state — and not widely released — shows that a comparison of voter lists and driver’s license information turned up a list of nearly 182,000 people who may not be U.S. citizens.

State officials, however, note that some of those on list may have become citizens after first getting their driver’s licenses. Still, the decision to screen the voter rolls for non-citizens could result in tens of thousands voters being dropped in the middle of a critical election year.

President Barack Obama won Florida four years ago, but recent polls have shown that he is neck-and-neck with likely GOP nominee Mitt Romney. The 2000 election between George W. Bush and Al Gore was decided by just 537 votes in the Sunshine State.

“The Department of State has a duty under both state and federal laws to ensure that the voter registration rolls are current and accurate,” said Chris Cate, a department spokesman.

There are currently more than 11 million active registered voters in the state.

Florida law requires voters to be a U.S. citizen residing in the state. Florida also does not allow someone to vote if they are a convicted felon and have not had their civil rights restored.

State officials said they did not know yet if any of the people on the list voted illegally in past elections.

The state has been responsible for helping screen voters since 2006 when it launched a statewide voter registration database.

Prior to the launch of the database, Florida had come under fire for previous efforts to remove felons from the voting rolls, including a purge that happened right before the 2000 presidential election. An effort to remove felons back in 2004 was halted after it was discovered that the list drawn up by the state had problems.

The state database is supposed to check the names of registered voters against other databases, including ones that contain the names of people who have died and people who have been sent to prison.

Driver’s license numbers had been used to verify the identity of someone who had registered to vote but apparently the state was not checking citizenship status prior to last year. The state does not give driver’s licenses to illegal immigrants, but it does grant them to legal visitors.

Cate said the list of 182,000 people was drawn up by checking first and last names, date of birth and either a driver’s license number, a Social Security number or an address. Most of the matches had identical driver’s license numbers, names and birthdates. A state document shows that out of the nearly 182,000 identified that more than 172,000 were active voters, meaning they had cast ballots in recent elections or registered recently.

The state is taking the matches using other databases to try to confirm if the voter is not a U.S. citizen. Florida has asked for access to a federal database maintained by the Department of Homeland Security but so far the U.S. government has turned the state down.

The initial list of more than 2,600 voters given out by the state to supervisors shows the names of people who registered all the way from the late ’50s to as recently as 2011. One Hillsborough County man on the list registered to vote in 1959.

Some have questioned the timing of the state’s push to remove voters from the rolls. It comes while Florida is still in court over a 2011 law that curtailed early voting hours and tightened rules for groups registering voters. Legislators said the law was needed to protect the integrity of the state’s elections, but the U.S. Department of Justice has questioned some of the changes.

“Of course Floridians are entitled to have confidence in the integrity of the voter rolls, and anyone not eligible should be removed and not permitted to vote,” said Howard Simon, executive director of the American Civil Liberties Union of Florida. “But the ‘potentials,’ ‘possibles,’ ‘might-bes’ that are the basis for this initiative by the Secretary of State don’t yet add up to voter fraud. Based on Florida’s regrettable experience with voter purges, it would be a mistake to rely on the accuracy of the state’s data.”

Republican Party of Florida chairman Lenny Curry defended the state push.

“To now learn that thousands of illegal votes could be cast across our state is chilling and threatens the confidence people need to have in our elections,” Curry said in a statement.” Any amount of fraud or illegality in this system is too much.”